Foreword

The development of this PAS was facilitated by BSI Standards Limited and it was published under licence from The British Standards Institution. It came into effect on 31 October 2020.

Acknowledgement is given to Richard von Goetze, as the technical author, and the following organizations that were involved in the development of this PAS as members of the steering group.

•	Anglia Ruskin University
•	Avient Corporation, Clariant Plastics & Coatings Int.
•	Department for Business, Energy & Industrial Strategy (UK)
•	Fera Science Ltd
•	Impact Solutions
•	Imperial College London
•	Polymateria Ltd.
•	WRAP

Acknowledgement is also given to the members of a wider review panel who were consulted in the development of this PAS.

The British Standards Institution retains ownership and copyright of this PAS. BSI Standards Limited as the publisher of the PAS reserves the right to withdraw or amend this PAS on receipt of authoritative advice that it is appropriate to do so. This PAS will be reviewed at intervals not exceeding two years.

The PAS process enables a speciﬁcation to be rapidly developed in order to fulﬁl an immediate need in industry. A PAS can be considered for further development as a British Standard or constitute part of the UK input into the development of a European or International Standard.

Information about this document

Text introduced by or altered by Corrigendum No. 1 is indicated in the text by tags . Minor editorial corrections are not tagged.

This publication can be withdrawn, revised, partially superseded or superseded. Information regarding the status of this publication can be found in the Standards Catalogue on the BSI website at bsigroup.com/standards, or by contacting the Customer Services team.

Where websites and webpages have been cited, they are provided for ease of reference and are correct at the time of publication. The location of a webpage or website, or its contents, cannot be guaranteed.

Use of this document

It has been assumed in the preparation of this PAS that the execution of its provisions will be entrusted to qualiﬁed and experienced people, for whose use it has been produced.

Presentational conventions

The provisions of this PAS are presented in roman (i.e. upright) type. Its requirements are expressed in sentences in which the principal auxiliary verb is “shall”.

Commentary, explanation and general informative material is presented in italic type and does not constitute a normative element.

Where words have alternative spellings, the preferred spelling of the Shorter Oxford English Dictionary is used (e.g. “organization” rather than “organisation”).

Contractual and legal considerations

This Publicly Available Speciﬁcation does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.

Compliance with a Publicly Available Speciﬁcation cannot confer immunity from legal obligations.

0 Introduction

The use of plastics and particularly polyoleﬁn-based plastics has signiﬁcantly increased over the past decades in many applications.[1] Driven by low costs and strong supply chains, polyoleﬁns have become the material of choice for many product applications. The result of this widespread use has meant that the end-of-life scenarios of these materials has come under ever-increased scrutiny. There are four major end-of-life scenarios of plastic materials. [2]

a)	landﬁll;
b)	incineration/waste-to-energy;
c)	mechanical recycling; and
c)	litter or leakage into the natural environment.

Whilst well-known standards and/or industry-accepted protocols exist for determining the applicability or performance of a plastic material in scenarios a), b) and c), previous standards in scenario d) have identiﬁed guidelines, but have not speciﬁed outcomes. In addition, they have sought to pre-determine the type of degradation process, rather than producing numerical criteria associated with the performance of the material under the stated test conditions.

NOTE 1 Similarly to standards within scenarios a), b) and c) for end-of-life of plastic materials, which do not overlap with each other when evaluating a plastic material, this PAS does not overlap with standards relating to landﬁll, incineration or recycling of plastics. This PAS provides data on the material only related to the end-of-life scenario as stated in scenario d): littering or leakage into the natural environment.

Within all plastic materials, polyoleﬁn-based plastics are the most littered category (approx. 50% of total). [2] More speciﬁcally, 75% of all fugitive plastic is land based.[3][4] It is widely accepted that fugitive plastic on land goes through a process of weathering, normally resulting in the generation of microplastics, followed by limited soil biodegradation depending upon the environmental conditions.[3]

NOTE 2 A deﬁnition of microplastics can be found in Annex G.

The problem is that polyoleﬁns are hydrocarbon-based materials that are resistant to environmental stimuli and inert to biological attack. Due to the ever-growing problem of plastic pollution and the need to innovate within current polyoleﬁn-based packaging, additive-based solutions are being proposed as biodegradable innovations within polyoleﬁnic materials. Although these additive-based innovations have been known for some time, previous standardization efforts have covered only speciﬁc aspects of polyoleﬁn use, such as durability (via weathering testing), degradation or loss of physical properties due to aging over time or biodegradation under selected conditions. The primary objective of this PAS is to provide a standard speciﬁcation that provides numerical data on the biodegradability of a given polyoleﬁn containing a speciﬁc biodegradable additive under open-air terrestrial conditions. The PAS is speciﬁcally designed to simulate the overarching process of biodegradability in an unmanaged environment, as in the case of littering or unmanaged disposal. It does not provide data on how a polyoleﬁnic material would perform under managed biodegradable end-of-life scenarios such as industrial or home composting, anaerobic digestion, or organic recycling.

NOTE 3 Biodegradability in unmanaged aquatic or marine environments is not considered in this PAS. These environments will be considered upon revision of this PAS depending upon available standards and evidence.

To achieve the objective of this PAS, internationally accepted existing standards in relation to the three key stages of concern with respect to biodegradability in an open-air terrestrial environment will be referenced accordingly. These standards will be further augmented in line with written protocols to specify the conditions and timeframes used for the testing at each stage. The three stages represented are:

1)	weathering of the polyoleﬁnic material under speciﬁc conditions and timeframes, after which chemical analysis proves that the polyoleﬁnic material has been transformed into a wax containing a speciﬁed carbonyl index;
2)	an assessment of the eco-toxicity of the wax using three sentinel species to determine that the wax presents no hazardous or inhibiting effects; and
3)	biodegradation of the wax under mesophilic conditions using exclusively soil as the medium for the test to reﬂect unmanaged disposal conditions. NOTE 4 An overview of the approach and pass-fail criteria can be found in Annex A. NOTE 5 Specifying that the biodegradation testing achieves a degree of mineralization greater than 90% avoids the generation of microplastics.

The PAS aims to standardize the effectiveness of technologies that impart biodegradability within polyoleﬁns by providing data on the performance of the tested technology under the stated conditions. Only by meeting the requirements of the standardized testing in all stages of this PAS is a technology within a given polyoleﬁnic material composition deemed to be compliant.

This PAS does not specify the origin of the raw materials used in the polyoleﬁn composition. Claims around bio-based content are to be made in accordance with relevant standards. In addition, the PAS does not specify the use-life or durability aspects of the polyoleﬁnic material under evaluation.

NOTE 6 If an assessment of the bio-based content of a polyoleﬁnic material is desired, further reading of BS EN 16640 and BS EN 16785‑1 is recommended.

NOTE 7 The compatibility of innovative polyoleﬁn packaging entering the market and its current recycling streams is covered by relevant industry recycling protocols.

The PAS is not intended for making claims of biodegradability, nor for product (self-) declaration. Compliance with the PAS would provide the numerical evidence to support claims about the performance of the technology within polyoleﬁns in alignment with BS EN ISO 14021.

NOTE 8 Attention is drawn to the legal requirements of the territory of use of the polyoleﬁnic material.

1 Scope

This PAS speciﬁes requirements of polyoleﬁnic materials enhanced with an additive technology that imparts biodegradability in an open-air terrestrial environment. This PAS speciﬁes the standards to be used for evaluating the performance of the tested polyoleﬁnic material at each stage, whilst within these protocols it speciﬁes the conditions and maximum timeframes the testing is to be conducted in. Furthermore, it speciﬁes the chemical analysis and the numerical limits required to meet compliance with the PAS at the end of each stage of testing.

Thus, this PAS covers:

a)

polyoleﬁn composition and additive technology under evaluation;

b)

alignment of speciﬁc standardized protocols for testing at each stage, notably:

1)	weathering exposure of test polyoleﬁnic materials for a deﬁned period of time, including chemical analysis to yield quantiﬁable measurement of chemical transformation into a wax;
2)	eco-toxicity testing upon the wax to ensure no hazardous substances are present; and
3)	biodegradation testing under mesophilic on soil conditions.

c)

standardized testing protocol to be used at each stage of evaluation as well as for chemical analyses;

d)

reporting of the data at the end of each stage of testing and the speciﬁcations to indicate compliance with the PAS.

This PAS does not cover:

•	managed biodegradable end-of-life scenarios such as industrial or home composting, landﬁll and anaerobic digestion;
•	unmanaged aquatic environments of freshwater of marine habitats, including the damage that bioaccumulation of plastic pollution creates in these ecosystems;
•	durability testing of the polyoleﬁnic material prior to any chemical or biological transformation;
•	the suitability or compatibility of the polyoleﬁnic material to be mechanically, chemically or organically recycled;
•	the life cycle assessment analysis of the polyoleﬁnic material combined with the biodegradable additive technology;
•	self-declared claims of biodegradability outside the framework of an appropriate standard such as BS EN ISO 14021; or
•	the requirement of the use of independent third-party certiﬁcation for claims of conformance to the PAS.

This PAS is intended to be used by plastic or plastic technology manufacturers looking to obtain data as to the performance of the biodegradability of an additive technology within a polyoleﬁnic material in an open-air terrestrial environment. In addition, this PAS provides testing laboratories with a standardized protocol to evaluate polyoleﬁnic materials for conformance to the PAS.

In addition, other standards agencies, national laboratories or academic research groups could use the test method described in this PAS as a universal baseline methodology of evaluating the biodegradability of new technological discoveries within polyoleﬁns.

2 Normative references

3 Terms, deﬁnitions and abbreviations

3.1 Terms and deﬁnitions

3.2 Abbreviations

4 Weathering of polyoleﬁns

4.1 Categorization of the polyoleﬁnic material prior to weathering

4.2 Selection of polyoleﬁn samples

4.3 Weathering procedure for samples

4.4 Chemical analysis procedures

4.5 Chemical analysis criteria to achieve after weathering

4.6 Reporting of weathering tests and chemical analysis

5 Eco-toxicity evaluation and testing of samples

5.1 Assessment of potentially biologically hazardous substances upon the surface of the polyoleﬁnic material before weathering

5.2 Assessment of eco-toxicity of wax after weathering

5.3 Reporting of eco-toxicity testing

6 Biodegradation of wax after weathering

6.1 Assessment of biodegradation

6.2 Reporting of biodegradation testing

Bibliography

PAS 9017:2020

Plastics. Biodegradation of polyolefins in an open-air terrestrial environment. Specification

Current

Published:

31 Oct 2021